The present invention relates to automotive radiators, and more particularly to a self-piercing radiator drain valve which is implemented in a radiator, particularly a radiator having no integrated drain valve.
Motor vehicles having internal combustion engines generally rely upon a radiator for cooling of the engine. This is accomplished by a coolant liquid circulating through passages in the engine also circulating through the radiator. The radiator has at least one reservoir tank and a fluidically interfaced heat exchanger composed of a serpentine tube interfaced with fins. As the hot coolant from the engine passes through the tube, heat of the coolant is given up to the atmosphere so that at the other end of the tube a cooler coolant is returned to the engine.
One aspect of maintenance is the ability to drain coolant from the radiator. Until recent advances in coolant chemistry, former formulations of coolant required its periodic changing. Accordingly, radiators have been conventionally equipped with an integrated drain valve composed of a hand operated stop cock located at the bottom of the reservoir tank. Not only does this drain valve involve an inherent cost, the placement involves design-required packaging so that service personnel can gain access thereto.
However, modern coolants generally do not need changing except at extremely high mileage. Added to this has been the development of improved seals and joints, and decreased need to lower coolant level due to servicing for other reasons, for example because of improved powertrain quality and durability.
Therefore, since modern vehicles have the ability to go for an extremely long time (or even never in the course of its life cycle) without need of the coolant drainage, the need for an integrated drain valve has become lessened. This creates the possibility that radiators could be manufactured and installed without the cost and design involvement associated with an integrated drain valve. The problem is, however, how to drain such a radiator if the need should one day arise.
Accordingly, it would be desirable if a radiator produced without an integral drain valve could somehow be retrofitted to have a drain valve later in the life cycle of the motor vehicle.
The present invention is a self-piercing radiator drain valve which is implemented in a radiator requiring the coolant therein to be drained, particularly a radiator having no integrated drain valve.
A radiator has feet (or sprues) which serve as lower attachment points for the radiator in a motor vehicle. Each foot has a blind bore, wherein the blind of the bore is defined by a bore end wall. For least one of the feet, the bore wall is situated vertically beneath an adjoining reservoir tank of the radiator. This foot will provide a valve passage of the self-piercing radiator drain valve according to the implementation methodology of the present invention.
A self-piercing valve body is provided which includes a drive head at one end of a shaft, a threaded section of the shaft adjacent the drive head, a piercing tip attached to the shaft opposite the drive head, and a resilient seal adjacent the piercing tip. The self-piercing valve body is sized to cooperate with the aforementioned foot to collectively provide the self-piercing radiator drain valve according to the present invention.
In operation, the self-piercing valve body is placed, piercing tip first, into a selected blind bore located underneath an adjoining reservoir tank and threadably driven further thereinto via the drive head. The threading causes the piercing tip to penetrate the bore end wall, thereby resulting in the blind bore becoming the valve passage of the self-piercing radiator drain valve. Thereafter, the self-piercing valve body is unthreaded, whereupon a valve orifice, which has been formed in the bore end wall by the piercing, permits coolant to drain out of the radiator reservoir tank through the valve passage. When it comes time to refill the radiator with coolant, the self-piercing valve body is again threaded into the blind bore, whereupon the seal provides coolant tight sealing with respect to the valve orifice for the remaining life of the radiator. At any time in the future, coolant draining and refilling can again be performed by unthreading and then rethreading the self-piercing valve with respect to the blind bore, as recounted.
Accordingly, it is an object of the present invention to provide a self-piercing radiator drain valve for automotive radiators, particularly radiators having no integral drain valve, which permits coolant drainage and subsequent coolant re-fill.